Our invention relates to an inking mechanism for printing presses such as a rotary relief press, and more specifically to such an inking mechanism designed for the ease of the cleaning of its constituent rollers.
As is well known, the printing ink is transferred from an ink fountain to the plate cylinder via a succession of rollers (see FIG. 1 of the drawings attached hereto). The rollers include a fountain roller dipped in the ink fountain, and a drawout roller alternately movable into rolling engagement with the fountain roller and the first of a series of ink rollers. A problem with such a printing press inking mechanism, as heretofore constructed, has been the cleaning of the inking rollers. All the inking rollers must be washed clean of the printing ink as for a change of colors or when the press is to be held out of operation for an extended period of time. The resulting downtime of the printing press has been substantial, particularly for the sheet fed machine that requires a frequent change of ink colors.
The conventional cleaning practice has been to jointly revolve all but the fountain roller of the inking rollers and to apply a solvent onto the revolving rollers. Dissolved by the solvent, the printing ink flows from one roller to another to be doctored off one of the rollers adjacent the plate cylinder. All but the fountain roller of the inking rollers have thus be capable of cleaning automatically. The fountain roller has been incapable of automatic cleaning with the other rollers because it has been held out of rolling engagement therewith. Accordingly, for cleaning the fountain roller, the printing ink has first been drained from the fountain, and the roller has been manually wiped as with a doctor or with a piece of cloth impregnated with a solvent, at the cost of considerable time and labor.